Control for oil filters



1930 c. R SHORT v CONTROL FOR OIL FILTERS Filed June 3, 1926 PatentedNov. 4, 1930 f UNITED STATES PATENT or-Flea oHARLEs R. sHOR'r, orDAYTON, OHIO, AssrenoR T0 GENERAL Mo'roRs RES CH oORPoRA'rION, orDETROIT, MICHIGAN, A CORPORATION or DELAWARE CONTROL FOR, OIL FILTERSApplication filed June s, 1926.. Serial No. 113,488.

This invention relates'to improvements in refining devices and moreparticularly to such devices used for the'purpose of refining orfiltering the lubricant for internal combustion engines.

One of the difficulties encountered in the employment of existing typesof filters arises after the filter has been in use for a time andthe-separated dirt and foreign matters tend to partially clog the filteror strainer member, offering increased resistance to the fluid flow. Insuch event there is a material difference in pressure on the respectivesides of the filter member. The increased resistance to the flow offluid through the filter raises the pressure on the inlet side andcorrespondingly lowers the pressure on the outlet side. This differencein pressure may exceed the structural strength of the filtering medium,and as a result, the force or pressure breaks down or punctures thefilter wall, allowing all the dirt previously separated to flow throughthe free passage, and destroying all subsequent filtering action.

It is-among the objects, of the present in'vention to prevent the filtermember from breaking down or becoming punctured due to ex- A cessiveinequalities of pressure in the respective sides of the filter and toautomatically limit the difference of pressure and maintain itrelatively uniform. Y

Referring to the drawing in which the refining device is shownin;section,'the numeral 20 designates a tank comprising a body portion21 provided with a removablehead 22 and a bottom 23. The bottom 23 andcover 22 are both provided with a central inner extension about which acoarse screen element 24 is adapted to fit. Inside of the screen elementthere is provided a filtering member 25, which may be of any suitabletype, but shown in the drawing as comprising a plurality of sheets offibrous material placed in stacked relation. The screen 24, and thefiltering member contained therein, provide a partition wallin the tank20 dividing the tank lnt-o an intake chamber 26 on one side and anoutlet chamber 27 on the other side of said partition.

Leading into the intake chamber 26 is V conduit 28, one end of which issecured in an aperture formed in thebottom 23 while the opposite end isin communication with a passage 29 formed in the housing 30. Anotherconduit 31 communicates with the outlet passage 29, said conduit beingconnected with any suitable fluid circulating pump or the like, notshown in the drawings. The passage formed by conduits 31 and 28andpassage 29 may be termed the'inlet passage.

Bottom 23 is apertured to receive aconduit 32 which communicates withthe outletcham- V ber 27 and with a passage 33 formed in housing portion34. Another conduit 35 leads from the passage 33. Passage formed byconduits 32 and 35 and passage 33 maybe termed the outlet passage.

The housing 30 and the housing portion 34 are connected together bymeans of screws as shown at 36. 7 Housing 30 is recessed to form chamber37 the end of said chamber communicatingwith passage 29 and beingprovided l with a flange 38. I-Iousingportion 34 has a passage-34 ofsmaller transverse diameter than the chamber 37, said-passage formingcommunication between the passage 33 and the chamber 37 A plungercomprising a shank portion 39 and a head portion 40 isprovided in thepassage 34 and chamber 37 respectively. The head portion '40 restsagainst the flange 38 and is normally held in engagement therewith bymeans of a spring 41 interposed between said head portion 40 and housing34. The shank 39 of the plungerextends from the chamber'37 through thepassage 34 its end normally being flush with the wall of the passage, asshown in the drawing.

When'the fluid is being forced through the conduit3 l, in thedi'rectionofthe arrow, it

' will flow through passage 29, and conduit 28 into inlet chamber 26,the pressure forcing said fluid through the filtering member 25 and.into the outlet chamber 27. From this out- 5 let chamber fluid willpass through conduit reduce the efliciency of said member and olfer '7increased resistance to theflllid: flow;

The excessive pressures in the passage 29 'will tend to push the'plungerupwardly or away from passage QQagainstthe efi ec-tof the spring 41thusca-using the shank portion 89 ofthe plun er to extend intothepassage-'33 as shown in t 1e dotted line on the drawing. Ihse'rti'on ofthe shank portion 39 into the passage33 will restricttheflow of fluidtherethrough, and thereby cause a back pressure in the outlet chamber oftank 20. Back pressure'in this chamber will counteractpressures-intheinlet'chamber 26 and maintain the pressures in the respectivepassagesrel-ativel uniform, thereby eliminating the brea ing or tearing down ofthe filterwall. lilxcessive pressure in the passage 29 will causethe'restriction in passage 33 to be correspondingly increased and whenthe pres;- sure in said; inlet passage is again reduced, the restrictionin the outlet passageis rela- 7 tivelyreducedl Thus it'will be seen thatthe pressure in the outlet chamber will be con trolled in accordancewith thevarying pressures in the inlet passage, so that thepressure insaid inlet chamber will not materially-exceed that in the outlet chamberand there will be no tendency for the inletpressure to force its waythru the filter wall','by breaking down or puncturing thefilter wall. 1

" While the form -of'e'mbodiment of theinvention as herein disclosed,constitutes a preferre-d form, it isto be understood that otherforms-might be adopted, all coming Within the scope of theclaimswhichfollow.

What is claimed is as follows 1 1; The combination of a filter havinginlet and outletpassages and'means; for main-taining' a; substantiallyuni-form pressure" difler- I entialin the'respective passages:

2; The combination of a filterhavin-ginlet and outlet passages, means insaid-" 'outl et and inlet passages movable in response to an increase-inpressure in. said inlet to r'estric't the cross-sectional area of saidoutlet passage. 3L A refining-device comprising in fcombi- 6i nation, afiltering member includin'ganinlet pendent upon the pressure of thefluid being introduced into the inlet chamber, for pro viding a backpressure in the outlet chamber,

whereby to control the pressure in the inlet chamber.

4L. A refining device comprising in combination, a filtermg member1nclud1ng an 1nlet chamber adapted to receive a fluid under pressure; anoutlet chamber; conduits for both the inletand outlet chambers; means:in the outlet conduit adapted to'impede the flowof fluid therethrougaandmeans -in the inlet chamber, connected with the-impeding means in theoutlet chamber, for controlling the said impeding means in accordancewith the pressure of the fluid'in the inlet conduit. 5; Arefinii'i-g-device comprising in combination, a filtering memberincluding: an inlet chamber adapted to receive a fluid under pressure;an 'outlet chamber; conduits for both the inlet and outlet chambers; avalve in the outlet conduit; anda control forsaid valve, in the inletconduit, adapted to operate the valve in accordance with thepressure ofthe fluid in the'inlet conduit. r a

6. A refiningdevicecomprising in combination a filteringmemberincludingfan"inlet v chamber adapted; to receive a fluidunder'pressure; an outlet chamber; conduit's for both the inlet and outletchambers;- a valve 'liousing including passages to which are con--nected the inlet and outlet conduits-respect'ively; and a plunger valveinterposed'between said passages,andadapted to-be operated by thevarying pressure of the fluid in the inlet conduit passage to controltheflow of fluid through' the outlet conduit pass-age. 7. VA refiningdevice comprising in combination a filtering member including an inletchamber adapted to receive a fluid under pressure; an outlet chamber;conduits for both the inlet and outlet. cl1ambers,a-housing' I.including 'a'passage connected tofthe inlet conduit; a passageconnected to the outlet conduit; a third passage connecting bothof saidpassages; and a plunger in said third passage, including a headportion"f;orming a movable partition between the inl'etand thirdpassages and a shank'portion th'e end of which forms a portion ofthewall of the outlet passage, said plunger being adapted to be operatedby the pressure of the fluid in the inlet passage to; control the flowof fluidin the outlet passage in accordance: with the saidpressure in{the inlet passage.

8'. In combination Wit-11 afilter, illet and outlet pipes for saidfilter, means connecting said inlet and outlet pipes, and a new contr'olvalve in saidmeans for-maintaining a substantially equal pressuredifierential be tween; the inlet and outlet pipes,

gi lhe comb'nation ofclaim S, said fvalve being spring pressed andadapted'torest'riet said outlet pipe and urged by said spring away fromsaid outlet pipe.

' 10. The combination of claim 8, said valve operated in one directionby the pressure in the inlet pipe to restrict the outlet pipe and by aspring in the opposite direction to remove the restriction.

11. In a flow control for oil filters, an inlet and an outlet for saidfilter, said control positio-ned between said inlet and said outlet andcomprising a housing, a plunger operating in said housing, said plungeroperated in one direction by the oil pressure in the inlet to restrictthe outlet, and a spring for operating said plunger in the oppositedirection to clear the outlet of the restriction.

12. The combination of claim 11, said plunger having an enlarged headresting on a flange in said housing.

13. The combination of claim 11, said spring surrounding said plungerand confined between a head on the plunger and the hous- 1 4 Thecombination of a filter having inlet and outlet passages, and movablemeans between said inlet and outlet passages and responsive to increasein pressure in the inlet for maintaining a constant pressuredifferential between inlet and outlet passages, said means alsocontrolling the flow of fluid from the outlet passage in accordance withthe pressure of the fluid in the inlet passage.

15, The combination of a filter having a filtering material and inletand outlet passages, and means for limiting the passage of fluid throughthe filtering material when the fluid pressure in the intake passageexceeds a certain value, said means maintaining a constant pressurediflerential between inlet and outlet passages.

16. A refining device comprising in combination, a filtering memberincluding an inlet chamber adapted to receive a fluid under pressure, anoutlet chamber, and means dependent upon the pressure of the fluid beingintroduced into the inlet chamber, for providing a back pressure in theoutlet chamber, whereby to control the pressure in the inlet chamber,said means also maintaining a constant pressure differential betweeninlet and outlet chambers.

17. A refining device comprising in combination, a filtering memberincluding an 1nlet chamber adapted to receive a fluid under pressure, anoutlet chamber, conduits for both the inlet and outlet chambers, meansin the' outlet conduit adapted to impede the flow of fluid therethrough, and means in the inlet chamber, connected with the impeding meansin the outlet chamber, for controlling said impeding means in accordancewith the pressure of the fluid in the inlet conduit, said means alsomaintaining a constant pressure differential between inlet andoutletconduits.v

18. A refining device comprising in combination, a filtering memberincluding an inlet chamber adapted to receive a fluid under pressure, anoutlet chamber, conduits for both the inletand outlet chambers, a valvein the outlet conduit, and a control for said valve,

in the inlet conduit, adapted to operate the valve in accordance withthe pressure of the fluid in the inlet conduit, said control alsomaintaining a constant pressure diflerential between inlet and outletconduits.

In testimony whereof I aflix my signature.-

CHARLES R. SHORT.

